Agricultural implements such as disc harrows having a tool supporting wing that can be folded over the main tool supporting frame are known. The folding feature is desirable for transport and storage. Provision of that feature is subject to the requirement that when the harrow, or like implement, is in operation each wing must have a certain degree of freedom of motion up and down, relative to the main body, to adapt its operation to the contours of the ground surface under treatment. While in the present embodiment the setting of the depth control is common to both wings and the main body of the machine, this may be varied without reference to the present invention.
The raising and folding and the unfolding and lowering of the wings of a wing disc harrow by hydraulic controls from a pulling tractor by the present invention is simple and dependable and does not interfere with the ability of the wings and the main body section to perform on varying contours and consistencies of the soil to be operated upon. It is fully controllable as to depth of operation by known means, preferably in the form of ground engaging wheels which, by their common setting, control depth of operation and are controlled by the operator on the operating tractor, preferably by hydraulic control. These desirable control features are understood in the art.